Google+ Followers

Wednesday, August 26, 2015

Stress can cause bad food choices and compromise long term goals.

Maier et al. show that more immediate rewards are likely to be chosen following stress because stress increases immediate reward signaling in the amygdala and striatum during choice. Subjects were stressed by having to hold a hand in ice water as long as possible, and then asked to select between more and less healthy food choices while in an MRI scanner, knowing that they would be expected to eat of their picks at the end of the test.

Important decisions are often made under stressful circumstances that might compromise self-regulatory behavior. Yet the neural mechanisms by which stress influences self-control choices are unclear. We investigated these mechanisms in human participants who faced self-control dilemmas over food reward while undergoing fMRI following stress. We found that stress increased the influence of immediately rewarding taste attributes on choice and reduced self-control. This choice pattern was accompanied by increased functional connectivity between ventromedial prefrontal cortex (vmPFC) and amygdala and striatal regions encoding tastiness. Furthermore, stress was associated with reduced connectivity between the vmPFC and dorsolateral prefrontal cortex regions linked to self-control success. Notably, alterations in connectivity pathways could be dissociated by their differential relationships with cortisol and perceived stress. Our results indicate that stress may compromise self-control decisions by both enhancing the impact of immediately rewarding attributes and reducing the efficacy of regions promoting behaviors that are consistent with long-term goals.